1. Field of the Invention
The present invention relates to a battery pack and, in particular, to a battery pack for electrical hand-held power tools.
2. Description of the Prior Art
A battery pack for electrical hand-held power tool contains a plurality of rechargeable current cells, e.g., Li-ionic current cells. During charging, in particular during rapid charging, the generated heat of the current cells should be removed to prevent a damaging overheating of the current cells. Usually, the battery housing has a plurality of aeration openings which provide for flow along the cells of a cooling air current that is generated by an associated charging apparatus.
European Publication EP-1 069 637 discloses a battery pack with cooling openings and a sealed block of arranged parallel to each other, current cells located between two plates. The plates are provided with pressure distributing openings, with flow paths running between separate openings. However, the cooling openings, which are provided on opposite sides of the battery pack, facilitate penetration of dirt and moisture into the battery pack, which reduces its service life.
German Publication DE-100 55 158 discloses a battery pack with cooling openings provided on one side of the pack. The battery pack includes two walls formed of current cells and internal air distribution means for uniform cooling. The cooling air distribution means includes two spaced from each other plates extending along the current cells. With this arrangement, three air streams are formed transverse to the cell axes, with two streams flowing along opposite sides of the wall, which is formed by the cells, in the same direction. The air streams that flow in the same direction transverse to the axial extent of the current cells course, because of heating of the streams, produce a non-uniform and, thereby, inefficient cooling which, in case of local heat accumulation, reduces the services life, despite the cooling.
Accordingly, an object of the present invention is to provide a battery pack with a technologically simple efficient cooling.